This section provides background information related to the present disclosure which is not necessarily prior art.
Inertia dampers are known for smoothing the output of rotary stepper motors and the like, but, to date, no such elements have been used with rotary valve elements for automotive exhaust systems, such as snap-action valves with a rotary valve plate and a bias return spring. Such valves can present vibration and noise problems while rotating due to resonance of the valve flap and bias spring.